Designers from three major international firms spoke at the Nasher Sculpture Center Wednesday evening. KERA’s Jerome Weeks reports they are finalists in what may be Dallas’ biggest urban design challenge: merging downtown with the Trinity River in a way that’d make both more appealing.

Wednesday’s talk was the opening event of The Connected City Design Challenge — which Dallas’ CityDesign Studio and the Trinity Trust have launched, along with such groups as Downtown Dallas and the Real Estate Council. Proposals are being solicited for how to link Dallas’ downtown core with the riverfront. The chief hurdle is the impassable tangle that’s there now, the freeways, levees, industrial sites and the Trinity’s wide, neglected floodplain. The hope is to make the area amenable to housing, recreation and retail – and to bridge downtown with West Dallas.

The competition is two-tiered, open to regular citizens and to professionals. The three professional finalists are OMA-AMO, the firm of Rem Koolhaas, familiar to Dallasites as the co-designer of the Wylie Theatre. RBTA — Ricardo Bofill Taller de Arquitectura — is a Barcelona company, while Stoss + SHoP are Boston urbanists combined with New York architects.

To many Dallasites, the riverfront has seemed a hopeless snarl, a barrier between the city and the river – complicated, of course, by a possible tollway inside the floodplain and all the questions about the Army Corps of Engineers and the levees. The surprise Wednesday was seeing designer after designer explain how other cities have turned similar, depressingly complicated wastelands into handsome, livable, usable spaces. The basic issue is reversing the flood-control projects in the ’20s through ’40s that essentially separated downtown from the Trinity River and isolated the river between massive levees. Put more simply, the issue is how to blend urban living with nature. Chris Reed of Stoss + SHoP said in his remarks, “Landscape is really important — the idea that you can start with nature in the city, that you can really have it as the kernel for good city making.”

But in North Texas, nature includes floods and brutal heat. Ricardo Bofill of RBTA extolled the simple benefits of shade trees to soften and blend nature and citylife: “It’s all about planting. If I had a million dollars, first thing I would do is spend it in trees. I would really just look for the right species and plant it downtown. And that would create shadows, that would create a place where you could live in a comfortable and beautiful way.”

The proposals moved between the global-gigantic and the intimate and ‘granular.’ Bofill’s urban design projects, often in Barcelona, Italy and France, have a sweeping, European poetry to them that varies between the truly elegant and the kitschy. Stoss has worked in American cities such as Milwaukee and New York on thorny, ugly waterfronts, wrestling them into esplanades, urban parks and ‘festival centers’ where water and cites intermingle. For this project, the typically big-picture, techno-forward OMA is working with Mia Lehrer + Associates, a firm whose largest project is the revitalization of the 51-mile long Los Angeles River corridor, turning a concrete gulley into a scenic, recreational “linear park,” planted with indigenous species.

All three proposals will be on display beginning in October, and each firm will give a talk at the Dallas Museum of Art in the coming months. The deadline for the public, open competition is Oct. 3.